As for Goats issue, I can see why Nefario wouldn't send him the bitcoins if the address was altered in any way, even if it was "just" a space. And putting his email entirely within quotes was odd and uncharacteristic of usual communications, and would send up red flags for me too.
That is really not fair. You're making inferences and speculation in favor of Nefario, effectively rewarding him for his silence. It's not fair to expect Goat, or anyone else, to refute every argument Nefario might hypothetically make while Nefario gets to see which arguments Goat can and cannot disprove before he has to take any position. That just makes it too easy to lie. ("What if Nefario says X, can you disprove that?" "Oh, you can, what about Y?" "Oh, you can, what about Z?" "Oh, you can't?" And then five minutes later Nefario says Z.)
Sure, you could perhaps speculate why Nefario might have done what he did. But I can speculate that Goat can disprove each of those speculations, should those be positions Nefario takes. You have to confine yourself to the arguments people are actually making and not expect hypothetical positions they might take to be proactively refuted by opposing parties.